1. The Prior Art
U.S. Pat. No. 4,897,246 issued Jan. 30, 1990 discloses a type oxidation chamber in which a liquid contaminated by undesirable organic compounds is treated. As the liquid passes through the oxidation chamber, it is subjected to intense ultraviolet (UV) radiation from high-powered UV lamps mounted inside quartz tubes that extend through the liquid in the chamber. Simultaneously the liquid is subjected to chemical attack by the injection of hydrogen peroxide. U.S. Pat. No. 4,897,246 has been assigned by Ronald L. Peterson to the assignee of the present invention, Peroxidation Systems, Inc. of Tucson, Ariz., as have the following patents.
U.S. Pat. No. 4,952,376 issued Aug. 28, 1990 discloses how a large tank-like oxidation chamber can be divided by baffles to provide either series or parallel flow paths as required by the liquid being processed.
U.S. Pat. No. 4,968,489 issued Nov. 6, 1990 shows the application of a fluoroethylene propylene (FEP) sleeve around the quartz tube that contains the ultraviolet lamp used in processing the liquid. The FEP sleeve facilitates cleaning of the quartz tube and serves to protect it.
U.S. Pat. No. 5,037,618 issued Aug. 6, 1991 discloses cladding the walls of the oxidation chamber with a UV-reflective material such as polytetrafluoroethylene (TEFLON.RTM.) or polyvinylidene fluoride (KYNAR.RTM.). Also disclosed is a way of partitioning the tank-like oxidation chamber to provide a segmented flow path of considerable length, adaptable to the application of a succession of treatments to the liquid.
All of the patents referred to above are incorporated by reference into the present disclosure.
Notwithstanding the ingenuity of the inventions described in the above patents, the treatment process continues to produce fouling of the quartz tubes and of the interior of the oxidation chamber. The fouling reduces the optical efficiency of the chamber to the point where the processing must be interrupted and the quartz tubes removed for cleaning. The walls of the chamber may also be cleaned at the same time. Such interruptions are highly undesirable. This is the central problem addressed by the present invention.